Electrical heating device.



G. A. HUGHES & T. M. UAVEN. ELECTRICAL HEATING DEVIGE.

APPLICATION EXLED JUNE 11, 1910.

1,049,488. Patented Jan. 7, 1913.

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ML (8 Q-MAVIPO VK/ I, g WA U. A. HUGHES & T. M. GAVBN.

ELECTRICAL HEATING DEVICE.

APPLICATION FILED JUNEII, 1310.

Patented J an. '7, 1913.

2 SHEETS-SHEET 2 STATES PATENT oration i i 1 r GEORGE A. AND TREVOR M.CAVEN, OF CHICAGO, ILLINOIS, ASSIGNOIRS T0 HUGHES: ELECTRIC HEATINGCOMPANY, OF CHICAGO, ILLINOIS, A COBYORATIQIT .150 ILLIiiOI 7 '0 allwhom, it may concern:

Be it known that we, GEORGE A. HUGHES and TREVOR Mg CAvnN, residents ofChicago, in the county of Cook and State of Illinois,

'5' have invented certain new and useful Im- =provements in ElectricalHeating Devices,

of which the following is a full, clear, and precise specification.

Our invention relates to electrical heat- 10 ing devices, and concernsparticularly an improved form of heating unit, the arrangement of suchunit in a stove frame, and the electrical connections and control forthe unit. i

Among the salient objects of our invention are to provide a heating unitwhich has a maximum heating efliciency with a minimum of Volume andsurface; to construct the heating wire supporting block of the unitofmaterial which is highly conductive toheat, so that this supportingblock will quickly take on the heat generated by the windings to therebyrelieve the windings of intense heat which might cause burningthereof,and to add its heat radiating surfaceto that of the windings; to providea supporting base or block for the unit, which base or block isconstructed of heat insulatingmaterial to thereby confine the radiation-01 heat from the unit block and windings to. objects set over the unitto be heated, to

' provide a plurality of resistance sections for the unit and improvedelectrical connections whereby said resistance sections can bet-put intocircuit in various combinations to produceflow1 'degrees of heat,inter1nedi= "degreesf of heat, and high degrees of to provide improvedterminal memonthe unit forthe resistance sections I mils for'detachableengagement with each ther so that the unit can be applied or removedfrom the stove frame without the necessity of disconnecting any wires orconductors, and so that the installation or removal of a unit will beautomatically ac companied=by its connection with or disconnectionfrom'the current supply circuit; and

in general to provide for improved construction and operation ofdevices'of the character referred to.

The nature of our invention is' clearly brought *out'in the followingspecification Specification 0! Letters 2 ate'nt.

mproved companion terminal members the supporting base, and to adapt thete'r- ELECTRICAL HEATING D'Evrcn.

Patented Jan. '7, 1913.

Application filed Junejl, 1910. Serial mi. 566,298.

and shown on the accompanying drawings, in which drawings.

Figure 1 is a perspective View of astove, showing a heating unit inplace thereon, Fig. 2 is. plain view of. a heating-unit, together withcircuit controlling arrangement therefor, and showing. thecircuit-controlling switch mechanism in on'e position, Figs. Qfand 2"show the switch. mechanism in different positions,' Fig. 3 showstheheating unit inside elevation andfthe 'inclosing block and part of thestove topin sectionon line Fig. 1, Fig. 4 is abottom view of the heatingunit, 5'is a plan view of the supporting base, F1g. 6 is,-an end viewofa block partly in section, and showing-amodified construction,andfliigslfl and 8 are end views of part of aunit showing other modifiedconstructions. j V

Referringto Figs? 2 and 3, block 1 of the heat-ing'nnitin the form of arectangular plate having a centralv longitudinal ridge Q, and. at eachside Of-illlS ridge is a plurality of narrower ridges substantially"semi-cylind -.1 t which accoinfriodate resist) ions in the form of wirecoils. hejends the forming ridges terminate a distance short of the ends7 of the block to leave fiat transeverse sections 6 and 7'fotiaccommodating the various terminal screws 8, under whose headstheends of the resistance coils are seciii'di in elec trical contact, theheads of-thes screws being preferably belovi the uppe p l' ridges. Fivesuch resistance [sections are shown at each side of the cent ridge 2,al-' though any number of such se trons could, of course, be provided.

In Figs. 2 and M between the resistance section ends, are'illusa trated.Referring to the resistance sections as a, b, c, d, e, f ,-g, h-, a andj,thfe sections at the circu it connections one end are connected as,follows: and e, (Z Y and f,g and i, and 7?, and g; and. at ithe other.end the sections. areconneoted as follows: a and 0,5 and d, e and y,andl.f' and h, 'the various connectinginembers 9 bei g either in theform of wires orof bands, whose ends are electrically connected with*the'fterminal block, as shown in Fig. 4. A conductor plate screw/s8 bynuts- 10 on the underside oi". the

11 is held against the bottom of thebloch and in electrical contact withthe terminal screw ofresistance'section aby means his nut 16,,

which plate -extendsjinwardly and is provided with a downwardlyeitending contact pin 12. A similarconductor plate 13 is secured .to theterminal screwofresistance section b and has the downwardly extendingcontact pin 14, ,i-Two conductor plates 15 and 16 are connected togetherat one end ai'id support a downwar' 1y extending conr't'act pin LF-,theopposite ends of the plates The supportin being secured to the terminalscrews of the resistance sections 2' and 7', these plates forming adirect connection between the outer ends of these sections. The contactpins 12,14 and 17 are adapted to engage with terin'inal jaws provided onthe supporting base-18. Referring to Figs. 1, 3 and 5, this suppbrtingbase is of cylindrical outside contour and has a square central pocket19 of substantially the same size as the heatin unit block, so that theheating unit bloc can be readily applied therein,-. as shownparticularly in Figs. 1 and 8. At one corner of the pocket 19 terminalplates 20 and 21 are secured against the bottom of the pocket bymeans ofscrews 22 and 23 extgpd ing through the floor 24' of the supporting baseand threading into the plates. The plate 20 mounts a spring jaw 24, andthe plate 21 mounts a spring jaw 25, these spring jaws extendingupwardly and in position to receive and to clamp the contact pins 12 and14 of the heating unit. At the opposite corner of the supporting base. aterminal plate 26 is held against the bottom of the pocket by a screw 27passing through the floor. 24 and threading into the plate, the end ofthe plate supporting a spring jaw 29 in position to receive the contactpin 17 on the heating unit. With this arrangement, when a unit isdropped into the supporting base, its contact terminals will engage withthe terminal jaws, and electrical connection is thus automaticallyestablished, and upon the removal of the heating unit from. the base thecontact pins are withdrawn from the terminal. jaws and the electricalconnections automatically broken.

As shown in Figs. 1 and. 3, the top 30 of the stove S is deflecteddownwardly to form the cylindrical pocket 31 for receiving thesupporting base. The supporting block 1 of the heating unit ispreferably construct ed of"materia1such as quartz composition "which ishighly conductive to heat, so that as the resistance sections are heatedthe material in the support-mg block will take on heat and thus relievethe resistance sections of intense heat which might result in burningout of the sections. supporting block will distribute theheat and willadd to the total radiating surface of the unit. h ating unit tructed orheat insulating: asbestos. so as to, confine is, howev r mater "i thespring jaw zed heat to the resistance sec-.

tions and their supporting block, and to confine the generated heat toupward flow against the objects placed over the base to be heated.

The stove may be of any suitable construction. The formshown in ,Fig. laccommodates only one heating unit, but it isobyious that any number ofheating units can be applied to dillerent. stoveconstructionaand,

that heating units may alsobe applied in ovens or other heatingcompartments, of the stove for baking, water heating, or other purposes,

By referring to Figs. 2 and 3 the supply circuit arrangement for theun'itcan be readily understood. .A switch A is shown comprising twoblades 33 and 34 connected with the main supply conductors L411, the 1blade 33 at its end having the arcuate ex tension 3;}. Contact buttons36 and 37 and a contact plate 38 are provided for engage-- ment with theswitch blades. The contact 5 buttons36 connects with the conductor 39leading to t-he screw 22 connected with the and button 37 connects withconductor 40, which leads to screw 23 connested withkswitchjaw 25, whilethecontact P ate 38 connects with conductor 41wvhich leads to screw 27connected with spring jaw- 29. When the switch parts arein-theposit-i'on shown in Fig. 2 current will flow from the mainconductor L through the switch blade 33, button 36, conductor'39,;-screw22,= spring jaw 24, contact pin 12, conductor plate 11 totheterminal screw of windingv section a, then through resistance sectionsa, c, a, gand ,6,- throZghconduetor-a plates 15 and 16, then throu tactpin 14,.spr1ng jaw- 25, screw-s23, con-f line .L'.

h resistance-sections j, k, j, (Z and I) to conductor strip 13, con'+=-fore, all in series to offer the greatestr... amount of resistance andtherefore togw 'a minimum degree of heat. If the; switchis moved to theposition shown in Fig. *2". the, .switch' blade 33 through itsfextlensionflfi'. remains in contact with the button 36. but.

the switch blade 34 leaves but-ton 37,aud en gages with thecontact plate38,: and the; circuit will boas follows: from.thc main line.v L,switch'iblade 33, extension 35, buttrmailfiw conductor 39, screw 22,spring jaw 24, rc-= sistance sct-ionso, c, c, g andzi, conductor plate15, contact pin 17-, conductor tl-,-con+ a switch blad -0 Jinc lhr Withthisarrangement onlyoiie-halfiof .the

resistance Emotions are inserted andztheirea mt'crm sistance reduculonc-half to, giv

-l h ating conditions If thesivitchuis by its-ex .ensionJ 5;,

is preferably of t e same heat conducting dividing, part .of the currentflowing through conductor 39 andresistance sections a, c, e, g and i tothe contact pin 17 and the other part flowing through conductor 40 andthrough resistance sections b, d, f, h and j tothe contact. pin ,17, thecurrent then returning through conductor 41, contact 38 and switch blade34 to line L. With this arrangement there are two parallel circuitsthrough the resistance sections, each including one-half of theresistance sections, and

we have the maximum heating conditions. Thus, by setting the switch tovarious posi-.

tions, minimum, intermediate or max1mum heatingconditions can beestablished. The switch mechanism can be of a construction as shown inFi s. 2, 2 and 2", or in the form of a snap switc A (Fig. 1) or of anyother suitable st le, and is preferably mounted on the stove i rame inany convenient glposition. Other combinations of the resistance sectionsand circuit could, "of course, be pro vided or added, and the switchmechanism correspondingly modified tobeactu'ated to are therefore,practically entirely exposed.

In". *ig. 6 I have shown a modified arrangement, which involves theapplication of a filler f in the grooves to partly or-wholly covertheresist'ance sections, and the filler material as that f thesupporting block.

In the modification shown 1n Fig. 7 noridges or grooves are provided,the block being flat on both faces and the sections 5 bein molded orcast into the block preferab y near. the upper surface thereof, theheatfrom the sections being transmitted to the material of the block. Inthcmodification in Fig. 8 the ridges and channels are provided, but thesections, instead of lying in the grooves, are molded or cast in theridges near the apexes thereof In the heating mechanism-of our invention, as described, the units are of simple and of inexpensiveconstruct-ion and produce the most eflicient heat conditions Jwith aminimum of weight and volume; Not only I ,do the resistance sectionsbecome heated, but

the entire supportin block forthe sections takes on heat to re ieve thesections, and.

this block, together with the sections, gives a maxi-mum radiatingsurface. The supporting base forlthe, unit, being ofheat insu-.

lating material, will prevent loss ofheat and will concentrate the heatagainst the objects to be ,heated. If a single resistancesection'burnsout it can quickly be replaced by a new section, or theentire unit can be readily lifted from its base and replaced by a newone. By means of the switching mechanism various circuit combinationsare provided for the sections to produce the desired heating conditions.

We do not desire to be limited to the forms and arrangements which wehave both in construction and arrangement are possible which would stillcome within the. scope of our invention, and we therefore claim thefollowing:

1. A heating unit for electrical stoves, comprising a supporting blockformed of material of high heat conductivity, a plurality of individualresistance conductors on said block,-terminals on said block for saidconductors, and cross connectors for said terminals for adapting saidconductors for connection in vario combinations with a current su plycircuit.

2. In co material having high heat conductivity,a plurality ofindividual heating coils ar-' ranged on 'said block, terminals on saidblock for each coil, cross connectors on said block and connectingvarious coils in'elec trical relation, a source of cu1'rent, circuitsfor supplying current flow, from said source ination, a supporting blockof shown and described, as other modifications v to said coils, and asin 16 switch mechativity, a plurality of individual heating conductorssupported on said block, and terminals on said block for saidheating'conductors, said terminals being adapted for electricalengagement with the terminals in said pocket upon application of saidblock in said pocket.

4. In combination, a stove top having a depressiom a base block forsaiddepression, said base block being'of heat insulating material andhaving a pocket, a supporting block fitting in said pocket, :1 pluralityof individual resistance conductors on said sup porting block, terminalson said block for said resistance conductors, and electrical terminalsmounted in said pocket and adapt" ed to be engaged by the terminals ofsaid block upon application of the block in said Jpocket.

5. In electrical heating mechanism, the combination of a base formed ofheat insulating material and havingsa pocket, elec-' trical terminalsockets mounted in said pocket and adapted for connection with a currentsupply source, a supporting block of material possessing high heatconducfivity, 'a plurality 'of individual heating con- In witnesshereof, we. hereunto subscribe ductors supgot td in parallel on saidblock, our names this 3rd day of JuneiA D1910. and terrain; (mm on saidblqckfor said heat GEORGE A. -.=HUGHES.-- conductors, smdfefininal jadapted TREVOR-M. CAV-EN." 5 for engagement with sa' film} 'sobkqtsVv'xtnesses: Y

in the pocket of said bake upon application 4 CHARLES J-ISCHMIDT, ofsaid blok in said pocket. N ELLIE B. DpARBOnN.

